Optical sensitizing dyes containing a n-carbamylmethyl group



United States Patent OPTICAL SENSIIIZING DYES CONTAINING AN-CARBAMY-LMETHYL (moor Leslie G. S. Brooker and Donald W. Heseltine,Rochester,

N. Y., assignors to Eastman Kodak Compmy, Rocha ester, N. Y., acorporation of New Jersey NoDrawing. Application October 14, 1954,Serial No. 462,392

12 Claims. (Cl. 260-240.6)

This invention relates to cyaninedyes and methods for making them. Moreparticularly, this invention relates to cyanine dyes containing at leastone N-carbamylmethyl group and photographic emulsions containing thesenew dyes.

Accordingly, it is an object of our invention to provide new cyaninedyes containing a N-carbamylmethyl group. Another object is to providemethods for making these cyanine dyes Still another object is to providenew intermediates'for preparing these dyes, as well as a method formaking these new intermediates. Another object is to providephotographic emulsions sensitized with these new cyanine dyes. Otherobjects will become apparent from, a consideration of the follow ingdescription and examples.

The dyes of our invention can advantageously be represented by thefollowinggeneral formula:

oxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole,S-phenyloxazole, etc.), those of the benzoxazole series (e. g.,.benzoxazole, S-phenylbenzoxazole, S-methylbenzoxazole,6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole,5-methoxybenzoxazole, 6-methoxybenzoxazole, S-ethoxybenzoxazole,S-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), those of thenaphthoxazole series (-e. g., a-naphthoxazole, tinaphth-oxazole, etc.),those of the selenazole series (e. g., 4-methylselenazole,4-phenylselenazole, etc.), those of the benzoselenazole series (e. g.,benzoselenazole, S-methoxybenzoselenazole, 5-hydroxybenzoselenazole,tetrahyd-robenzoselenazol'e, etc.), those of the naphthoselenazoleseries (e. g., wnaphthoselenazole, p-naphthoselenazole, etc.), those ofthe *thi'azoline series (e. g., thiazoline, 4- methylthiazoline, etc),thoseof the Z-quinoline series (e. g., quinoline, S-methylquinoline,S-methylquinoline, 7-methylquinoline, S-methylquinoline,6-methoxyquinoline, -6-eth0X-yquinoline, 6-hydroxyquinoline,8-hydroxyqu'inoline, etc.), those of the 2-quinoline series (e. g.,quinoline, G-methoxyquinoline, 7-methylquinoline, 8 methylquinoline,etc.), those of the l-isoquinoline series (e. g., isoquinoline,3,4-dihydroisoquinoline, etc.), those of the 3-isoquinoline series (e.g., isoquinoline, etc.), those of the 3,3-dialkylindolenine series (e.g., 3,3-dimethylindolenine, 3,3,5-trimethylinodolenine,3,3,7-trimethylindolenine, etc.), those of the Z-pyridine series (e. g.,pyridine, 3-methylpyridine, 4-methylpyridine, 5-.

methylpyridine, G-methylpyridine, 3,4-dimethylpyridine,

3,5-dimethylpyridine, 3,6-dimethylpyridine, 4,5-dimethylwherein R and R1each represents an alkyl group, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, n-amyl, carboxymethyl, B-carboxyethyl,carbomethoxymethyl, carbethoxymethyl, ,B-hydrOx-yethyl, B-methoxyethyl,allyl (vinylmethyl), benzyl (phenylmethyl), carbamylmethyl (e. g.,carbamylmethyl, dimethylcarbamylmethyl, diethylcarbamylmethyl, etc.),etc., provided that at least R or R1 is a carbamylmethyl group, Rrepresents a hydrogen atom or a lower alkyl group (e. g., methyl, ethyl,etc.), X represents an acid radical, such as chloride, bromide, iodide,perchlorate, thiocyanate, benzenesulfonate, p-toluenesulfonate,methylsulfate, ethylsulfate, etc., d, n, and q each represents apositive integer of from 1 to 2, and Z and Z1 each represents thenon-metallic atoms necessary to complete a heterocyclic nucleuscontaining 5 atoms in the heterocyclic ring or 6 atoms in theheterocyclic ring, such as those selected from the group consisting ofthose of the thiazole series (e. g., thiazole, 4-methylthiazole,S-methylthiazole, 4-phenylthiazole, S-phenylthiazole,4,5-dimethyl'thiazole, 4,5-diphenylthiazole, 4-(2-thienyl)-thiazole,etc.), those of the benzothiazole series (e. g., benzothiazole,4-methylbenzothiazole, S-methylbenzothiazole, 6-methylben zothiazole,4-phenylbenzothiazole, S-phenylbenzothiazole, 4-methoxybenzothiazole,5-methoxybenzothiazole, S-methoxybenzothiazole, 4-ethoxybenzothiazole,S-ethoxybenzothiazole, tetrahydrobenzothiazole,5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole,S-hydroxybenzothiazole, fi-hydroxybenzothiazole, etc.), those of thenaphthothiazole series (e. g., a-naphthothiazole (i. e.,[2,11-naphthothiazole), B-naphthothiazole (i. e., [1,2]-naphthoth'iazole), 5-m,ethoxy-fl-naphthothiazole,S-ethoxy-Bmaphthothiazole, 7:methoxy-m-naphthothiazole, 8-methoxy-a-naphthothiazole, etc.), those of thethianaphtheno-7,6',4,5-thiazo1eseries (e, g.,4'-methoxythiadroxy'pyridine, etc.), etc.

According to our invention, we provide the new dyes represented byFormula I above wherein d represents 2 and Z and Z1 are identical (i.e., symmetrical carbocyanine dyes) by reacting together a cyclammoniumquaternary salt selected from those represented by the following generalformula:

a l f( -on -on),.-i :o-om

X1 wherein R, n and Zeach have the values given above,

and X1 represents an acid radical, such as those defined above for X,with an orthoester selected from those represented by the followinggeneral formula:

wherein R2 has the values given above and R represents a. lower alkylgroup (e. g., methyl, ethyl, etc.). Alternatively, these symmetricalcarbocyanine dyes wherein R2 represents a hydrogen atom can be preparedby condensing together an intermediate selected from those representedby Formula II above with a dialkoxymethyl carboxylate, such. asdiet'hoxymethyl acetate, which process is described in Dent and BrookerU. S. Patent 2,537,- 880, issued January 9, 1951. p

The new dyes of our invention represented by Formula I above wherein dis 2 and Z and Z1 are different from one another (i. e., unsymmetricalcarbocyanine dyes), and wherein R2 is a hydrogen atom, can be preparedby condensing a cyclamrnonium quaternary salt selected from thoserepresented by Formula II above with an intermediate selected from thoserepresented by the following general formula:

wherein R1, q, and Z1 each have the values given above, R3 represents acarboxylic acyl group, such as acetyl, propionyl, butyryl, isobutyryl,benzoyl, etc. (e. g., a carboxylic acyl group containing from 2 to 7carbon atoms), R4 represents an aromatic group, such as phenyl, mandp-tolyl, etc. (e. g., a mononuclear aromatic group containing from 6 to7 carbon atoms), and X2 represents an acid radical, such as those listedabove for X. Unsymmetrical carbocyanine dyes wherein R2 is an alkylgroup can be prepared according to the method described in Kodak BritishPatent 533,425, accepted February 13, 1941.

The new dyes of our invention represented by Formula I above wherein drepresents 1 (i. e., simple cyanine dyes) can be prepared by condensinga cyclammonium quaternary salt selected from those represented byFormula II, above with a cyclammonium quaternary salt selected fromthose represented by the following general formula:

where R1, q, X2 and Z1 each have the values given above, and R"represents a halogen atoms, such as iodine, or an alkylor arylmercaptogroup (e. g., methylmercapto, ethylmercapto, phenylmercapto, etc.).

The condensations of the compounds of Formula II with those of FormulasIII, IV and V can advantageously be accelerated by heating the reactionmixture, generally temperatures varying from room temperature (about 25C.) to the reflux temperature of the reaction mixture beingsatisfactory. The condensations can be carried out in the presence of aninert diluent, such as pyridine, nitrobenzene, ethanol, n-propanol,isopropanol, n-butanol, etc.

The condensations of the compounds of Formula II with those of FormulasIV and V can advantageously be carried out in the presence of a basiccondensing agent, such as the trialkylamines (e. g., triethylamiue,tripropylamine, triisopropylamine, tributylamine, triisobutylamine,triamylamine), N-all-zylpiperidines (e. g., N-methylpiperidine,N-ethylpiperidine, etc.), N,N-dialkylanilines (e. g.,N,N-dirnethylaniline, N,N-diethylaniline, etc.), etc.

We have also found that the intermediates selected from thoserepresented by Formula II above can be condensed together witha'compound selected from those represented by Formula III and a compoundselected from those represented by the following general formula:

VI Q\ wherein Q represents the non-metallic atoms necessary to completea heterocyclic nucleus containing from to 6 atoms in the heterocyclicring (as defined in column 3, line 57-column 4, line 60, of U. S. Patent2,666,761, issued January 19, 1954) to give merocarboeyanine dyes.Alternatively, these merocarbocyanine dyes can be produced by condensingtogether a compound selected from those represented by Formula IV abovewith a compound selected from those represented by Formula VI above.

We have also found that dicarbocyanine and tricarbocyanine dyescontaining a N-carbamylmethyl group can be prepared by condensing acompound selected from those represented by Formula II above with [3-anilinoacroleinanilhydrochloride (Hamer U. S. Patent 2,218,450) andglutaconicaldehydedianilide hydrochloride (Brooker U. S. Patent2,161,332, issued June 6, 1939), respectively.

We have found that tetracarbocyanine dyes containing a N-carbamylmethylgroup can be prepared by condensing a compound selected from thoserepresented by Formula II above together withpiperylenedialdehydeditrahydroquinalide iodide in the presence of abasic condensing agent, such as the trialkylamines listed above. Thesecondensations are preferably carried out in the presence of an inertdiluent, such as acetic anhydride (Dieterle et al., Z. w. P., vol. 36,pp. 68, 141).

The intermediates selected from those represented by Formula II abovecan advantageously be prepared by heating together a base selected fromthose represented by the following general formula:

wherein Z and it each have the values given above, with an amideselected from those represented by the following general formula:

VIII

Cl-CHzCITT-Rs Ito wherein R5 and Rs each represents a hydrogen atom or ao1-Nl o11-orr "L e-win cling-n n, 0 Rs wherein n, Z, R5 and Rs each havethe values given above. Heating i advantageously effected on a steambath and is continued until quaternation is substantially complete. Thechloride anion can be placed in the compounds of Formula IX according tothe method described in Brooker U. S. Patent 2,245,249 or 2,245,250,both issued June 10, 1941, or by simply adding an aqueous solution of asalt, the anion of which produces a more insoluble derivative of thecompound of Formula IX than the chloride derivative.

The following examples will serve to illustrate the manner whereby thenew dyes of our invention can be prepared.

Example I .3-diethylcarbamylmethyl-Z-mcthylbenzothiazolium chlorideCON(C2H5)2 Z-methylbenzothiazole (74.5 g., 1 mol.),chloroacetdiethylamide (74.5 g., 1 mol.), and sodium iodide (0.1 g.)were mixed and heated on the steam bath for ten days. The reactionmixture was then cooled and stirred with ether (500 ml.). The ethersolution was decanted and the residue washed with ether. The sticky saltwas then stirred with acetone ml.), chilled, filtered, and dried. Theproduct 24.2 g. (16 percent) was used Without further purification. M.P. 2312 C. dec. The quaternary iodide was prepared by adding sodiumiodide to an aqueous solution of the chloride.

Example 2.- 3'-diethylcarbamylmetkyl-3' cthyloxwlliacarbocyaninlMrchlaratc 3-diethylcarbamylmethyl 2 methylbenz-othiazolium iodide (1.5g., 1 mol.), Z-B-acetanilidovinyl-3-ethylbenzoxazolium iodide (1.7 g., 1mol.), and triethylamine (0.51 g., 1 mol. plus 30 percent excess) wereheated under reflux in ethyl alcohol (20 ml.) for twenty minutes. Thecrude dye was precipitated by the addition of water (100 ml.). Theaqueous solution was decanted and the residue dissolved in ethyl alcoholand precipitated -by the addition of aqueous sodium perchlorate. Theyield of crude dye was 1.03 g. (38 percent). Afiter fourrecrystallizations from methyl alcohol, the yield of purified dye was0.26 g. (9 percent). M. P. 151-3 C.

Example 3.3,3'-di(diethylcarbamylmethyl)-9-methylthiacarbocyanine iodideOH ti CH2 ([BH: I comm t. o'oNwiHm S-diethylca-rbamylmethyl 2methylbenz-othi'azolium chloride (2.99 g., 2 mol.) and ethylorthoacetate(3.24; g., 1 mol. plus 300 percent excess) were heated under reflux inpyridine (20 ml.) for one hour. The reaction mixture was chilled and thecrude dye precipitated by the addition of sodium iodide (2 g.) inwater(5.0 ml). The crude product, 1.65 g. (49 percent), was "filtered, washedwith water, and ether, and dried. After two recrystallizations frommethyl alcohol, the yield of purified dye was 1.05 g. (31 percent). M.P. 262-3 C. dec.

Example 4.3,3-di(diethylcarbamylmethyl) 9 -,-ethy lthiacarbocyanineiodide 3-diethylcarbamylmethyl 2 met-hylbenzothiazolium chloride (3.0g., 2 mol.) and. ethylorthopropionate (3.52 g., 1 mol. plus 300 percent)were refluxed. in pyridine (20 ml.) for thirty minutes. The reactionmixture was cooled and the crude dye converted to the iodide by theaddition of sodium iodide (2g.) in water (50 ml.). The crude dye (1.65g.,, 48 percent.) was, filtered off, washed with water and ether anddried. After two recrystallizations from methyl alcohol, the yield ofpurified dye was 1.20 g. (35 percent). M. P. 257-8 C. dec.

'furt-her purification. by adding aqueous sodium iodide to an aqueoussolution ml., 1 mol. plus 50 percent excess) were refluxed in ethylalcohol (20 ml.) for one hour. The reaction mixture was cooled and thecrudedye precipitated by the addition of ether (200 ml.) and then washedwith additional ether. The dye iodide was dissolved in ethyl alcohol,converted to the perchlorate by the addition of aqueous sodiumperchlorate and then filtered and dried. The yield of pure dye afterfour recrys-tallizations from methyl alcohol was 0.25 g. (10 percent).M. P. 226-7 C. dec.

Example 6.5-[(i-diethylcarbamylmethyl-Z(3H)benzothiazolylidene)-is0propylidene] 3 ethyl-2-thi0-2,4-

oxazolidinedione 3-diethylcarbamylmethyl 2 methylbenzothiazoliumchloride (2.99 g., 1 mol.), 3-ethyl-2-thio 2,4-oxazolidinedione (2.3 g.,1 mol. plus 50 percent excess), and ethylorthoacetate (3.2 g., 1 mol.plus percent excess) were refluxed in pyridine (20 ml.) for one hour.The crude dye (1.37 g., 32 percent) was thrownout of solution by theaddition of water (100 ml.), filtered, washed with water, and dried.After two recrystallizations from acetic acid, the yield of pure dye was0.75 g. (17 percent). M. P. 242-3 C. dec.

Example 7.-] diethylcarbamylmethyllepidinium chloride the.

CON(C2H5)2 Lepiid'ine (14.3 g., lmol.) and chloroacetdiethylamide (14.9g., 1 mol.) were mixed and heated on the oil bath at -120" C. for thirtyminutes. The reaction mixture was cooled and the crude product stir-redwith acetone, filtered, washed with acetone, and. dried. This crudeproduct (15.1. g., 52 percent) was used without A portion converted tothe iodide of the chloride melted at 212-13 C. dec.

7 Example 8.-1,1 -d i diethylcarbamylmethyl -4 ,4

carbocyamlne bromide Br l NOH2C ON(-C2H6)I 2,776,280 7 81-diethylcarbamylmethyllepidinium chloride (1.46 g., acetic anhydride(30 ml.) and stirred occasionally at 2 mol.) and diethoxymethylacetate(1.62 g., 1 mol. plus room temperature for one hour. The reactionmixture 300 percent excess) were heated under reflux in pyridine a thfilt d d th crude d t h d with (15 ml.) for twenty minutes. The reactionmixture was acetone (200 1,), water (200 L), d fi ll ith chilled and thecrude Product 74 P P 5 methyl alcohol (500 ml.). After recrystallizingfrom cipitated by the addition of aqueous sodium bromide. methyl alcoholthe yield of pure dye was 042 (7 The crude dye was filtered off, washedwith Water and ercent The bronze c t d acetone, and dried. After tworecrystallizations from dec rys a me POW er had methyl alcohol, theyield of pure dye was 0.60 g. (39 percent). M. P. 270-1 C. dec. 10

Example 9.1,1' di(diethylcarbamylmethyl)-10methyl- 4,4'-carb0cyarzineiodide OH; I

1-diethylcarbamylmethyllepidinium iodide (7.68 g., 2 ExampleI3.-3-carbamylmethyl-l-ethylthia-2-cyanine mol.), ethylorthoacetate(3.24 g., 1 mol. plus 100 peri did cent), and triethylamine (2.8 ml., 1mol. plus 100 percent) were heated under reflux in acetic anhydride ml.)for one hour. Reaction mixture was chilled, filtered, and the crude dyewashed with water and acetone, 5 and dried. After two recrystallizationsfrom methyl alcohol, the yield of pure dye was 1.21 g. (18 percent). 25(3:011 \N/ M. P. 195-6" 0. dec. Example 10.]diethylcarbamylmethyl-3-ethylthia 4'- f I carbocyanine iodide CHaCONHa s'30 /I O=CHOH=GH- \I-CHaCODKOnHs)! 3 carbamylmethyl 2methylbenzothiazolium iodide ITT 1.11 g.) (M. P. 249-50" C. dec.) and2-iodoquinoline 35 ethiodide (1.37 g.) were dissolved in absolute ethylall-diethylcarbamylmethyllepidinium chloride (1.46 g., cohol (20 a j:rnethylamine (0-34 1 m 2 l3 acetani1idoviny1 g ethylbenzothiazolium g.)was added and the reaction mixture heated under id 215 g 1 m andtriethylamine 5 g, 1 reflux for 20 minutes. The reaction mixture waschilled, mol.) were heated under reflux in ethyl alcohol (20 ml.) 0ether added With Stirring and the y filtered f fift i t Th ti i t washill d, oil and twice recrystallized from methyl alcohol. Yieldfiltered, and the crude dye (1.55 g., 54 percent) was 0.35 g. 21%, M. P.281-2 C. with decomposition. Washed with water and acetone, and dried.After two recrystallizations from methyl alcohol, the yield of purifieddye was 0.93 g. (33 percent). M. P. 2534 C. dec.

Example 11.1,1' di(diethylcarbamylmethyl) 4,4-tricarbocyanine bromideBlr (OzH5) NCOCHa-N =GH-CH=OHCH=CHOH=OH NCH2CON(CzH5):

1methylcarbanjlylmethyllepidinium chloride 8- Example 14. 3,3dicarbamylmcthylthiacarbocyanine 2 mol.), glutaconlcaldehydedianilidehydrochloride (2.85 5 iodide g., 1 mol.), and piperidine (2 ml., 1 mol.plus 20 percent) were suspended in ethyl alcohol (25 ml.) and S Sstirred at room temperature for thirty minutes. The reaction mixture wasthen filtered and the crude dye (1.65 G=OH-GH=0H-0 g., 27 percent) waswashed with water and ether and dried. After conversion to the bromideby the addition N N of aqueous sodium bromide and recrystallizing twice566; from methyl alcohol, the yield of pure dye was 0.51 g. (8 percent).M. P. 200-201 C. dec. 2- carbamylmethyl- 2- rnethylbenzothiazoliumiodide Example 12.1,1'-di(diethylcarbamylmethyl)-4,4'-tetracarbocyanineiodide 1-diethylcarbamylmethyllepidinium iodide (2.92 g., 2 (2.50 g.)and diethoxymethyl acetate (1.62 g.) were dismol. plus 100 percentexcess), piperylenedialdehydedisolved in pyridine (25 cc.). The reactionmixture was tetrahydroquinolide iodide (1.2 g., 1 mol.), acetic acidheated under reflux for 20 minutes, chilled, the dye fil- (lml.), andtriethylarnine (3 ml.) were suspended in tered off and washed well withwater. The dye was twice recrystallized from methyl alcohol. Yield 0.18g. 10%, M. P. 272-3 C. with decomposition.

Example ,15.3' carbamylmethyl-3-ethyl-oxa-zhiacarbocyanine iodide 3carbamylmethyl 2 methylbenzothiazolium iodide (1.11 g.) and2-5-acetanilidovinylbenzoxazole ethiodide (1.45 g.) were dissolved inabsolute ethyl alcohol (25 co.) in a 50 cc. flask. Triethylamine (0.34g.) was added and the reaction mixture heated under reflux for 15minutes. The reaction mixture was then chilled and ether (100 cc.) addedwith stirring. The ether layer was then decanted off and the residualdye washed with two 100 cc. portions of water. The dye was then twicerecrystallized from methyl alcohol. Yield 0.58 g., 35%, M. P. 259-60 C.with decomposition.

This dye was a good sensitizer and it was easy to obtain in a purestate, unlike the 3,3'-diethyl dye which is difficult to obtain pure.

Example 1 6 .1 ,1 -dicarbamylmethyl-4,4'-carb0cyanine iodide1-carbamylmethyllepidinium iodide (3.28 g.) (M. P. 236-8 C. doc.) anddiethoxymethylacetate (1.62 g.) were dissolved in pyridine (30 cc.) andthe reaction mixture heated under reflux for 20 minutes. The reactionmixture was thenchilled, the dye filtered ofi and washed with water andacetone. The crude dye was twice recrystallized from cresol. Yield 0.24g. 9%; M. P. 274- C. with decomposition.

Example J.7.- 1-carbamylmethyl 3-ethyl-0xa-4'- carbacyanine iodideornooNm Example 18.-1'-carbamylmethyl-3 ethyl-thfat-4- carbocyanineiodide 02H; I g lacarbarnylmethyllepidinium iodide, (1.64 g.),. 2-{3-acetanilidovinylbenzothiazole ethiodide (2.25 g.) and triethylamine(0.51 g.) were dissolved in ethyl alcohol (30 cc.). The reaction mixturewas heated under reflux for 15 minutes and then chilled. The crudedyewas filtered oft", washed with, water and acetone and twicerecrystal- 10lized from methyl alcohol. Yield 0.72 g., 53%; M. P. 293-4 C. withdecomposition.

All of the dyes of our invention are particularly useful inmanufacturing photographic, silver halide emulsions, serving to alterthe sensitivity thereof. Sensitization by means of our new dye is, ofcourse, directed primarily to the ordinarily employed,gelatino-silver-halide, developing-out emulsions. The dyes areadvantageously incorporated in the washed, finished emulsion and should,of course, be uniformly distributed throughout the emulsion.

in the preparation of photographic emulsions containing our new dyes, itis only necessary to disperse the dyes in the emulsions. The methods ofincorporating dyes in emulsion are simple and well known to thoseskilled in the art of emulsion making. It is convenient to add the dyesfrom solutions in appropriate solvents. The solvent must, of course, becompatible with the emulsion and substantially free from any deleteriouseifect on the lightsensitive materials. Methanol has proven satisfactoryas a solvent for the majority of our new dyes.

T he concentration of our new dyes in the emulsion can vary widely, i.e., from about 5 to about 100 mgs. per liter of fiowable emulsion. Theconcentration of the dye will vary according to the type oflight-sensitive material in the emulsion and according to the efiectsdesired. The suitable and most economical concentration for any givenemulsion will be apparent to those skilled in the art upon making theordinary tests and observations customarily used in the art of emulsionmaking.

"tributed throughout the emulsion.

To prepare a gelatino-silver-halide emulsion sensitized with one of ournew dyes, the following procedure is satisfactory: A quantity of the dyeis dissolved in methyl alcohol or other suitable solvent and a volume ofthis solution (which may be diluted with water) containing from 5 tomgs. of dye is slowly added to about 1000 cc. of agelatino-silver-halide emulsion, with stirring. Stirring is continueduntil the dye is uniformly dis- With most of our new dyes, 10 to 20 mgs.of dye per liter of emulsion suffices to produce the maximum sensitizingefiect with the ordinary gelatino-silver-bromide (including bromiodide)emulsions. With fine-grain emulsions, which include most of theordinarily employed gelatino-silver-chloride emulsions, somewhat largerconcentrations of dye may be necessary to secure the optimum sensitizingeffect.

The above statements are only illustrative and are not to be understoodas limiting our invention in any sense, as it will be apparent that ournew dyes can be incorporated by other methods in many of thephotographic Silver halide emulsions customarily employed in the art.For instance, the dyes can be incorporated by bathing a plate or filmupon which an emulsion has been coated, in the solution of the dye, inan appropriate solvent. Bathing methods, however, are not to bepreferred ordinarily.

Photographic silver halide emulsions which can advantageously besensitized by means of the new dyes of our invention comprise thecustomarily employed gelatinosilver-chloride,gelatiuo-silver-chlorobromide, gelatinosilver bromide, andgelatino-silver-bromiodide developing-out emulsions.

Photographic silver halide emulsions, such as those listed above,containing the sensitizing dyes of our invention can also contain suchadde'nda as chemical sensitizers, e. g., sulfur sensitizers (e. g.,allyl thiocarbamide,

thiourea, allylisothiocyanate, cystine, etc.), various gold compounds(e. g., potassium chloroaurate, auric trichloride, etc.) (see U. S.Patents 2,540,085; 2,597,856 and 2,597,915), various palladiumcompounds, such as palladium chloride (U. S. 2,540,086), potassiumchloropalladate (U. S. 2,598,079), etc., or mixtures of suchsensitizers; antifoggants, such as ammonium chloroplatinate (U. S.2,566,245), ammonium chloroplatinite (U. S. 2,566,263), benzotriazole,nitrobenzimidazole, 5- nitroindazole, benzidine, mercaptans, etc. (seeMees-- 2,776,280 11 12 The Theory of the Photographic Process, MacMillan5. The cyanine dye represented by the following Pub., 1942, page 460),or mixtures thereof; hardeners such formula: 3 as formaldehyde (U. S.1,763,533), chrome alum (U. S. S V S 1,763,533), glyoxal (U. S.1,870,354), dibromacrolein (Br. 406,750), etc.; color couplers, such asthose de- 5 U. S. application Ser. No. 771,380, filed August 29, 1947,

scribed in U. S. Patent 2,423,730, Spence and Carroll (now U. S. Patent2,640,776) etc.; or mixtures of such OHzCONHa I l CHrOONHz addenda.Dispersing agents for color couplers, such as those set forth in U. s.Patents 2,322,027 and 2,304,940, The cyanine y represented y thefollowms can also be employed in the above-described emulsions. m a

What we claim as our invention and desire secured by s 8 Letters Patentof the United States is: 1. A compound selected from those representedby the following general formula: 1 (IJHB i )i 1(-on=eH)liken(-o=oH .i1-6on on),I NJs R I 1 1 CHzC-N-Rs III CON(CIH6)1 CON(C2H5):

7. The cyanine dye represented by the following formula:

wherein R1 represents an alkyl group containing from 1 to 7 carbonatoms, R2, R5 and Rs each represents a 5 member selected from the groupconsisting of a hydrogen atom and a lower alkyl group, X represents anacid radical d, n, and q each represents a positive integer N/ \N offrom 1 to 2, and Z and Z1 each represents the nonmetallic atomsnecessary to complete a heterocyclic nu- 1 cleus, said heterocyclicnucleus being selected from the group consisting of those of thethiazole series, those of 52,52 cyamne dye represented by the followmgthe benzothiazole series, those of the naphthothiazole series, of thoseof the thianaphtheno-7,6,4,5-thiazole S 0 series, those of the oxazoleseries, those of the benzoxazole series, those of the naphthoxazoleseries, those of i o=CHOH=oH O the selenazole series, those of thebenzoselenazole series, r

those of the naphthoselenazole series, those of the thiazoline series,those of the 2-quinoline series, those of 0H: C2Hs 0104 thel-isoquinoline series, those of the 3-isoquino1ine ooNwHm series, thoseof the 3,3-dialkylindolenine series, those of the 2-pyridine series andthose of the 4-pyridine series. cyamne dye represented by the followmg2. A cyanine dye selected from those represented by 40 formula thefollowing general formula:

l CHI I O0N(O:H5)z 10. A process for preparing cyanine dyes comprisingcondensing a compound selected from those represented by the followinggeneral formula:

wherein R and R1 each represents a cli(lower alkyl) carbamylmethyl groupand X represents an acid radical.

3. A cyanine dye selected from those represented by the followinggeneral formula:

wherein R5 and Rs each represents a member selected from the groupconsisting of a hydrogen atom and a whereln R represents a lower alkylgroup, R1 represents lower alkyl group, n represents a positive integerof a diflower carbamylmethyl group: and X from 1 to 2, and Z representsthe non-metallic atoms Semis an Tadlcalnecessary to complete aheterocyclic nucleus, said hetero- A cyfamne dye Selected from thoserepresented by cyclic nucleus being selected from the group consistingthe followmg general formula: of those of the thiazole series, those ofthe benzothiazole series, those of the naphthothiazole series, those ofthe S f /C=GH NQ If R1 X n thianaphtheno-7',6,4,5-thiazole series, thoseof the oxazole series, those of the benzoxazole series, those of whereinR represents a di(lower alkyl) carbamylmethyl group, R1 represents alower alkyl group and X reprethe naphthoxazole series, those of theselenazole series, those of the benzoselenazole series, those of thenaphthoselenazole series, those of the thiazoline series, those of theZ-quinoline series, those of the l-isoquinoline series, those of the3-isoquinoline series, those of the 3,3-dialkylindolenine series, thoseof the Z-pyridine series and those of the 4-pyridine series, with acompound selected sents an acid radical. from those represented by thefollowing general formula:

13 mono-R2 wherein R2 represents a member selected from the groupconsisting of a hydrogen atom and a lower alkyl group and R represents alower alkyl group.

11. A process as defined in claim 10 wherein the condensation is carriedout in the presence of an inert diluent.

12. A process as defined in claim 11 wherein the inert diluent ispyridine.

References Cited in the file of this patent UNITED STATES PATENTS

1. A COMPOUND SELECTED FROM THOSE EPRESENTED BY THE FOLLOWING GENERALFORMULA: